1. Field of the Invention
The present invention relates to a photosensitive resin composition. More particularly, it relates to a photosensitive resin composition which is not affected by oxyen, capable of image formation, has an excellent sensitivity, water resistance, solvent resistance, acid resistance, alkali resistance, water developing property, and resolving power and can be used for the production of screen printing plates, second originals, planographs, reliefs, plano-intaglios, television fluorescent screens and the like, and for the precision metal processing of printed circuit substrates with resist images and the like.
2. Description of the Related Art
A photosensitive resin compound comprising a saponified poly(vinyl acetate) and a styrylpyridinium salt compound or styrylquinolinium salt compound is known (see Japanese Patent Publication No. 1306/85). This photosensitive resin compound has a high sensitivity, but has the following drawback. That is, the photoreaction of this photosensitive resin is a photocrosslinking reaction caused by the photodimerization of a styrylpyridinium salt compound or styrylquinolinium salt compound grafted to the saponified poly(vinyl acetate). Accordingly, the amount of the hydroxyl group contained in the saponified poly(vinyl acetate) in the photosensitive layer is not varied by irradiation, and therefore, has a disadvantage in that a high resolving power cannot be obtained because a significant swelling thereof occurs upon water development due to a poor water resistance at parts which have bee hardened by irradiation.
As a means for overcoming this drawback, an increase in the rate of introducing the styrylpyridinium salt compound or styrylquinolinium salt compound into the saponified poly(vinyl acetate) has been considered, but in this method, it is impossible to coat an aluminium plate or a gauze for screen printing with the photosensitive resin compound obtained because of an extensive increase of the viscosity of the aqueous solution thereof. The styrylquinolinium salt compound and the styrylpyridinium salt compound also are disadvantageous in that a satisfactory water resistance can not be obtained, probably because they contain a quaternary ammonium salt, or the crosslinking rate by photodimerization can not be increased to a satisfactory extent even if the rate at which the styrylpyridinium salt compound and the styrylquinolinium salt compound, are introduced is increased.
Another prior art discloses a photosensitive resin compound obtained from a saponified poly(vinyl acetate) and an N-methylolacrylamide or N-methylolmethacrylamide (see Japanese Patent Publication No. 5923/74). This photosensitive resin composition comprising a saponified poly(vinyl acetate) and an N-methylolacrylamide or N-methylolmethacrylamide has an excellent water resistance, but has the defects of a low resolving power and low sensitivity, or the like.
Accordingly, the prior art does not suggest that a photosensitive resin compound having a high sensitivity and excellent water resistance, solvent resistance and resolving power can be obtained by combining and introducing one or more of at least one of a styrylpyridinium salt compound of a styrylquinolinium salt compound and at least one of a N-methylolacrylamide or N-methylolmethacrylamide into the saponified poly(vinyl acetate).